NATION : Cracks Studied at Three Mile Island

HARRISBURG, Pa. — Engineers at Three Mile Island, site of the nation's worst commercial nuclear plant accident, are studying what could be two small cracks on the inside of the damaged reactor, a spokeswoman said today.

It is not yet known if the small lines that showed up on a remote television inspection of the reactor bottom are indeed cracks, said plant spokeswoman Mary Wells. They could be scales or rivulets of molten material left over from the March, 1979, accident, she said.

"We don't know the significance," Wells said, adding that a team of six engineers has been set up to study the situation.